Objects on Rails comes in three “editions”. There’s the one you can read for free online. There’s the $5 “download edition”. And I also offer a $20 “Sponsor Edition” for people who really feel like it’s worth more than $5, or who just want to see me do more stuff like Objects on Rails.

When I announced this Sponsor Edition, I promised a “special goodie” just for buyers of that version. I pondered for a long time what would make the perfect bonus for the people who were generous enough to pay $20 for a book they could read online for free. Then I met Sandi Metz at RailsConf, and started reading through a draft copy of her terrific upcoming book, Practical Object Oriented Design in Ruby. And I realized then that I knew what I wanted the bonus to be.

Last week Sandi was good enough to join me via Skype, and over the course of two sittings we had a wide-ranging conversation about Object Oriented design and Ruby. As a Smalltalk veteran, Sandi brings to the table a perspective which is deeply steeped in the highly dynamic, message-oriented OO tradition, and free of the static Java/C++-style baggage that so many of us (myself included!) bring to Ruby. She also has a gift for making nebulous concepts like “abstraction vs. concretion” accessible and immediately useful.

The final recording is a little over two and a half hours long. Some of the topics we discussed include:

How Smalltalk influences her approach to Ruby and OO

The meaning of “design”

Viscous code vs. exemplary code

How your design can affect how other programmers think about the domain

When to call code “good enough”, and why that should change based on your “audience” (who will read and modify the code).

Anthropomorphising objects: good thing or bad thing?

Focusing on messages rather than objects

Thinking about Roles instead of Classes

Refactoring and patterns

…and a heck of a lot more

If you bought the Sponsor Edition, you should already have a product update email in your inbox. If you bought the $5 download edition, you should also have an email in your inbox with a discount code, should you decide to “upgrade”. If you have neither, you can find both editions in my store.

Once again, I’d like to express my gratitude to all the people who support my writing, and especially those who were willing to drop $20 on a book they could read online for free. I hope you enjoy this recording as much as I enjoyed making it.